Is it worth protecting NCB?

I am trying to decide if it is worth paying for, I never had the ncb protection before but having seen a friend get a huge increase in her premiums after an accident I am considering taking it out.

My insurance is up for renewal next week
Fully comp and includes windscreen cover and breakdown asist with an excess of €125, car is 2l diesel 2001 is €469

and I emailed the insurance company the costs of insuring the NCB and this is what they came back with

3 different option of bonus protection,

Step-back bonus protection, This will protect 20% of your 50% discount in the event of a claim.
Protected no claims discount, this will allow you to have 2 claims in a 3 year period without looking your discount.
protected no claims discount with step back, this allows you again to have 2 claims in a 3 year period without loosing your discount and in the event you have a 3rd claim you discount will be stepped back to 20% on a 3rd claim.
To add option 1 to the renewal it would be €491.52
To add option 2 it would be €514.92
To add option 3 it would be €540.67